Navigate to Applications > Utilities > Disk Utility.

When Disk Utility is open, select the hard drive you want to break into a partition.

In the Partition tab, click the + button.

Enter a size and name for the new partition. Click Apply. It may take a few minutes for the process to complete.

Navigate to Applications > Utilities > Terminal.

Use the diskutil list command to see a list of drives connected to your computer. Take note of the disk name on the drive you want to partition.

This is the command to create a single partition:

diskutil partitionDisk /dev/disk2 GPT JHFS+ NewPartition 0b 

Replace /dev/disk2 with the name of your hard drive. Replace JHFS+ with the formatting of your choice. Changing NewPartition will change the name of your new partition. Lastly, 0b represents the size of the new partition. Adjust this to create a specific partition size.

Here’s an example showing the creation of multiple 10GB partitions:

diskutil partitionDisk /dev/disk2 GPT JHFS+ Partition1 10g JHFS+ Partition2 10g 

It may take a few minutes for the partition to be created. Congratulations! You’ve successfully split your hard drive.

Open the Start Menu, and enter the word format. Select Create and format hard disk partitions.

Alternatively, you can open the Disk Management tool by right-clicking a hard drive under This PC and selecting Format.

The Disk Management tool will load a list of hard drives connected to your machine. You can format external hard drives, flash drives, and internal drives from this list. Right-click the hard drive you want to format and select Format. Enter a name for the hard drive in the Volume Label field. Set the File system and Allocation unit size from the drop-down menu.

Open the Start Menu, and type cmd. Right-click Command Prompt and choose Run as Administrator.

When Command Prompt opens, type diskpart then press enter.

Type list disk then press enter. This will show everything from hard drives to USB drives. Note the number assigned to the hard drive you want to format.

Type select disk # to select a specific drive. Replace the # sign with the actual disk number. For example, you would use select disk 2 to select the second disk. Press enter.

Type clean and press enter. Next, enter create partition primary and press enter.

You need to define a file system format. For example, you can implement a NTFS file system with this command: format fs=ntfs

After you’ve successfully formatted the drive, you need to assign it a letter. Type the word assign and press enter. Congratulations! Your drive is formatted and ready to go.